Youqin Chen

Ursolic acid inhibits colorectal cancer angiogenesis through suppression of multiple signaling pathways.

Angiogenesis plays a critical role in the development of solid tumors by supplying nutrients and oxygen to support continuous growth of tumor as well as providing an avenue for hematogenous metastasis. Tumor angiogenesis is highly regulated by multiple intracellular signaling transduction cascades such as Hedgehog, STAT3, Akt and p70S6K pathways that are known to malfunction in many types of cancer including colorectal cancer (CRC). Therefore, suppression of tumor angiogenesis through targeting these signaling pathways has become a promising strategy for cancer chemotherapy. Ursolic acid (UA) is a major active compound present in many medicinal herbs that have long been used in China for the clinical treatment of various types of cancer. Although previous studies have demonstrated an antitumor effect for UA, the precise mechanisms of its anti-angiogenic activity are not well understood. To further elucidate the mechanism(s) of the tumorcidal activity of UA, using a CRC mouse xenograft model, chick embryo chorioallantoic membrane (CAM) model, the human colon carcinoma cell line HT-29 and human umbilical vein endothelial cells (HUVECs), in the present study we evaluated the efficacy of UA against tumor growth and angiogenesis in vivo and in vitro and investigated the underlying molecular mechanisms. We found that administration of UA significantly inhibited tumor volume but had no effect on body weight changes in CRC mice, suggesting that UA can suppress colon cancer growth in vivo without noticeable signs of toxicity. In addition, UA treatment reduced intratumoral microvessel density (MVD) in CRC mice, decreased the total number of blood vessels in the CAM model, and dose and time-dependently inhibited the proliferation, migration and tube formation of HUVECs, demonstrating UAs antitumor angiogenesis in vivo and in vitro. Moreover, UA treatment inhibited the expression of critical angiogenic factors, such as VEGF-A and bFGF. Furthermore, UA suppressed the activation of sonic hedgehog (SHH), STAT3, Akt and p70S6K pathways. Collectively, our findings suggest that inhibition of tumor angiogenesis via suppression of multiple signaling pathways might be one of the mechanisms whereby UA can be effective in cancer treatment.

Scutellaria Barbata D Don Inhibits Colorectal Cancer Growth via Suppression of Multiple Signaling Pathways

The pathogenic mechanisms underlying cancer development are complex and heterogeneous, involving multiple cellular signaling transduction pathways that usually function redundantly. In addition, crosstalk between these pathways generates a complicated and robust signaling network that is regulated by compensatory mechanisms. Given the complexity of cancer pathogenesis and progression, many of the currently used antitumor agents, which typically target a single intracellular pathway, might not always be effective on complex tumor systems. Moreover, long-term use of these agents often generates drug resistance and toxicity against normal cells. Therefore, the development of novel anticancer chemotherapies is urgently needed. Scutellaria barbata D Don (SB) is a medicinal herb that has long been used in China to treat various types of cancer. We previously reported that the ethanol extract of SB (EESB) is able to induce colon cancer cell apoptosis, inhibit cell proliferation and tumor angiogenesis via modulation of several pathways, including Hedgehog, Akt, and p53. To further elucidate the precise mechanisms of SB’s antitumor activity, using a colorectal cancer (CRC) mouse xenograft model in the present study, we evaluated the therapeutic efficacy and molecular mechanisms of EESB against tumor growth. We found that EESB reduced tumor volume and tumor weight but had no effect on body weight gain in CRC mice, demonstrating that EESB could inhibit colon cancer growth in vivo without apparent adverse effect. In addition, EESB treatment could significantly suppress the activation of several CRC-related pathways, including STAT3, Erk, and p38 signalings in tumor tissues, and alter the expression of multiple critical target genes such as Bcl-2, Bax, Cyclin D1, CDK4, and p21. These molecular effects lead to the induction of cancer cell apoptosis and inhibition of cell proliferation. Our findings demonstrate that SB possesses a broad range of antitumor activities because of its ability to affect multiple intracellular targets.

Pien Tze Huang suppresses IL-6-inducible STAT3 activation in human colon carcinoma cells through induction of SOCS3

IL-6/STAT3 is one of the most critical cellular signal transduction pathways known to malfunction in colorectal cancer (CRC). As a target gene of signal transducer and activator of transcription 3 (STAT3) signaling, suppressor of cytokine signaling 3 (SOCS3) can be quickly induced by interleukin-6 (IL-6) stimulation but it then strongly inhibits IL-6-mediated STAT3 activation, functioning as a negative feedback regulator of the IL-6/STAT3 pathway. Aberrant activation of STAT3 and/or reduced expression of SOCS are strongly correlated with carcinogenesis, which therefore becomes a promising target for the development of novel anticancer chemotherapies. Pien Tze Huang (PZH) is a well-known traditional Chinese formula that was first prescribed by a royal physician 450 years ago in the Ming Dynasty. It has been used in China and Southeast Asia for centuries as a folk remedy for various types of cancer including CRC. However, the precise mechanism of its antitumor activity remains largely unclear. In the present study, we found that PZH could significantly and dose-dependently inhibit IL-6-mediated increase of STAT3 phosphorylation levels and transcriptional activity in the human colon carcinoma HT-29 cells, resulting in the suppression of cell proliferation and the induction of apoptosis. In addition, PZH treatment profoundly inhibited IL-6-induced upregulation of cyclin D1 and Bcl-2, two key target genes of the STAT3 pathway. Moreover, PZH treatment increased the expression of SOCS3. These results suggest that PZH could effectively inhibit proliferation and promote apoptosis of human colon carcinoma cells via modulation of the IL-6/STAT3 signaling pathway and its target genes.

Pien Tze Huang inhibits tumor angiogenesis in a mouse model of colorectal cancer via suppression of multiple cellular pathways

Angiogenesis plays an essential role in cancer progression, which therefore has become an attractive target for anticancer treatment. Tumor angiogenesis is tightly regulated by multiple signaling pathways that usually function redundantly; in addition, crosstalk between these pathways forms a complicated network that is regulated by compensatory mechanisms. Given the complexity of pathogenic mechanisms underlying tumor angiogenesis, most currently used angiogenesis inhibitors that only target single pathways may be insufficient and probably generate drug resistance, thus, increasing the necessity for development of novel anticancer agents. Traditional Chinese medicines (TCM) are receiving great interest since they have relatively fewer side-effects and have been used for thousands of years to clinically treat various types of diseases including cancer. Pien Tze Huang (PZH), a well-known traditional Chinese formulation that was first prescribed 450 years ago, has long been used as an alternative remedy for cancers. However, the precise mechanism of PZHs anticancer activity remains to be further elucidated. Using a colorectal cancer mouse xenograft model, in the present study, we evaluated the effect of PZH on tumor angiogenesis and investigated the underlying molecular mechanisms. We found that PZH inhibited tumor growth since PZH treatment resulted in decrease in both tumor volume and tumor weight in CRC mice. In addition, PZH suppressed the activation of several signaling pathways such as STAT3, Akt and MAPKs. Consequently, the inhibitory effect of PZH on these pathways resulted in the inhibition of tumor angiogenesis as demonstrated by the decrease of microvessel density in tumor tissues. Moreover, PZH treatment reduced the expression of angiogenic factors including iNOS, eNOS, VEGF-A, bFGF as well as their specific receptors VEGFR2 and bFGFR. Altogether, our findings suggest that inhibition of tumor angiogenesis via suppression of multiple signaling pathways might be one of the mechanisms whereby PZH affects cancers.

Pien Tze Huang inhibits metastasis of human colorectal carcinoma cells via modulation of TGF-β1/ZEB/miR‑200 signaling network

Tumor metastasis, a complex process involving the spread of malignant tumor cells from a primary tumor site to a distant organ, is a major cause of failure of cancer chemotherapy. Epithelial-mesenchymal transition (EMT) is a critical step for the initiation of cancer metastasis. The processes of EMT and metastasis are highly regulated by a double-negative feedback loop consisting of TGF-β1/ZEB pathway and miR-200 family, which therefore has become a promising target for cancer chemotherapy. Pien Tze Huang (PZH), a well-known traditional Chinese formula first prescribed in the Ming Dynasty, has been demonstrated to be clinically effective in the treatment of various types of human malignancy including colorectal cancer (CRC). Our published data proposed that PZH was able to induce apoptosis, inhibit cell proliferation and tumor angiogenesis, leading to the suppression of CRC growth in vitro and in vivo. To further elucidate the mode of action of PZH, in the present study we evaluated its effects on the metastatic capacities of human colorectal carcinoma HCT-8 cells and investigated the underlying molecular mechanisms. We found that PZH significantly inhibited the migration and invasion of HCT-8 cells in a dose-dependent manner. In addition, PZH treatment inhibited the expression of key mediators of TGF-β1 signaling, such as TGF-β1, Smad2/3 and Smad4. Moreover, PZH treatment suppressed the expression of ZEB1 and ZEB2, two critical target genes of TGF-β1 pathway, leading to a decrease in the expression of mesenchymal marker N-cadherin and an increased expression of epithelial marker E-cadherin. Furthermore, PZH treatment upregulated the expression of miR-200a, miR-200b and miR-200c. Collectively, our findings in this study suggest that PZH can inhibit metastasis of colorectal cancer cells via modulating TGF-β1/ZEB/miR-200 signaling network, which might be one of the mechanisms whereby PZH exerts its anticancer function.

Patrinia scabiosaefolia inhibits colorectal cancer growth through suppression of tumor angiogenesis.

Angiogenesis is an essential process for tumor development and metastasis, therefore inhibition of tumor angiogenesis has become a promising strategy for anticancer treatments. Patrinia scabiosaefolia, a well-known Oriental folk medicine, has been shown to be effective in the clinical treatment of gastrointestinal cancers. However, the precise mechanism of its tumoricidal activity remains largely unknown. Using a colorectal cancer (CRC) mouse xenograft model, the human colon carcinoma cell line HT-29 and human umbilical vein endothelial cells (HUVECs), in the present study we evaluated the effects of an ethanol extract of Patrinia scabiosaefolia (EEPS) on tumor angiogenesis in vivo and in vitro, and investigated the underlying molecular mechanisms. We found that EEPS treatment significantly reduced the tumor volume in CRC mice and decreased the intratumoral microvessel density in tumor tissues. In addition, EEPS inhibited several key processes of angiogenesis, including the proliferation, migration and tube formation of HUVECs. Moreover, EEPS treatment suppressed the expression of VEGF-A in CRC tumors and HT-29 cells. Collectively, our data suggest that Patrinia scabiosaefolia inhibits CRC growth likely via suppression of tumor angiogenesis.

Ursolic acid promotes colorectal cancer cell apoptosis and inhibits cell proliferation via modulation of multiple signaling pathways

The development of colorectal cancer (CRC) is strongly correlated with the aberrant activation of multiple intracellular signaling transduction cascades including STAT3, ERK, JNK and p38 pathways which usually function redundantly. In addition, crosstalk between these pathways forms a complicated signaling network that is regulated by compensatory mechanisms. Therefore, most of the currently used and single-target-based antitumor agents might not always be therapeutically effective. Moreover, long-term use of these agents often generates drug resistance. These problems highlight the urgent need for the development of novel anticancer chemotherapies. Ursolic acid (UA) is a major active compound present in many medicinal herbs that have long been used for the clinical treatment of CRC. Although previous studies have demonstrated an antitumor effect for UA, the precise mechanisms of its tumoricidal activity are not well understood. In the present study, using CRC mouse xenograft model and the HT-29 human colon carcinoma cell line, we evaluated the efficacy of UA against tumor growth in vivo and in vitro and investigated the underlying molecular mechanisms. We found that UA inhibits cancer growth without apparent toxicity. Furthermore, UA significantly suppresses the activation of several CRC-related signaling pathways and alters the expression of critical target genes. These molecular effects lead to the induction of apoptosis and inhibition of cellular proliferation. These data demonstrate that UA possesses a broad range of anticancer activities due to its ability to affect multiple intracellular targets, suggesting that UA could be a novel multipotent therapeutic agent for cancer treatment.

Pien Tze Huang Inhibits Hypoxia-Induced Angiogenesis via HIF-1 α /VEGF-A Pathway in Colorectal Cancer.

Hypoxia-induced angiogenesis plays an important role in the development and metastasis of solid tumors and is highly regulated by HIF-1α/VEGF-A pathway. Therefore, inhibiting tumor angiogenesis via suppression of HIF-1α/VEGF-A signaling represents a promising strategy for anticancer treatment. As a traditional Chinese medicine formula, Pien Tze Huang (PZH) has long been used as a folk remedy for cancer in China and Southeast Asia. Previously, we reported that PZH inhibits colorectal cancer (CRC) growth both in vivo and in vitro. To elucidate the antitumor mechanisms of PZH, in the present study we used human umbilical vein endothelial cells (HUVEC) and colorectal carcinoma HCT-8 cells to evaluate the effects of PZH on hypoxia-induced angiogenesis and investigated the underlying molecular mechanisms. We found that PZH could inhibit hypoxia-induced migration and tube formation of HUVEC cells in a dose-dependent manner, although the low concentrations of PZH had no effect on HUVEC viability. Moreover, PZH inhibited hypoxia-induced activation of HIF-1α signaling and the expression of VEGF-A and/or VEGFR2 in both HCT-8 and HUVEC cells. Collectively, our findings suggest that PZH can inhibit hypoxia-induced tumor angiogenesis via suppression of HIF-1α/VEGF-A pathway.

Pien Tze Huang inhibits hypoxia‑induced epithelial‑mesenchymal transition in human colon carcinoma cells through suppression of the HIF‑1 pathway

Hypoxia-induced activation of the hypoxia-inducible factor 1 (HIF-1) signaling pathway is frequently observed in solid tumors and is strongly associated with numerous pathophysiological processes, including the induction of epithelial-mesenchymal transition (EMT), which result in cancer progression and metastasis. Thus, inhibiting EMT through the suppression of the HIF-1 pathway may be a promising strategy for anticancer chemotherapy. Pien Tze Huang (PZH), a well-established traditional Chinese medicine has been prescribed for >450 years and has been used for centuries to clinically treat various types of human cancer. We previously reported that PZH suppresses multiple intracellular signaling pathways and thereby promotes the apoptosis of cancer cells and the inhibition of cell proliferation and tumor angiogenesis. In the present study, to further explore the mechanisms underlying the antitumor action of PZH, HCT-8 human colon carcinoma cells were cultured under hypoxic conditions and the effect of PZH on hypoxia-induced EMT was assessed. Hypoxia was found to induce EMT-associated morphological changes in HCT-8 cells, including loss of cell adhesion and the development of spindle-shaped fibroblastoid-like morphology. In addition, hypoxia was observed to reduce the expression of the epithelial marker E-cadherin, but increase that of the mesenchymal marker N-cadherin. In addition, hypoxia significantly enhanced HCT-8 cell migration and invasion and induced the activation of the HIF-1 pathway. However, treatment of the HCT-8 cells with PZH significantly inhibited the hypoxia-mediated EMT and HIF-1 signaling. These findings suggest that PZH inhibits hypoxia-induced cancer EMT through the suppression of the HIF-1 pathway, which may be one of the molecular mechanisms by which PZH exerts its antitumor activity.

Qing Hua Chang Yin exerts therapeutic effects against ulcerative colitis through the inhibition of the TLR4/NF‑κB pathway

The activation of the Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway has been implicated as a key mediator in the pathogenesis of ulcerative colitis (UC); therefore, it has become an attractive target for the treatment of UC. Qing Hua Chang Yin (QHCY) is a traditional Chinese formula, which has been used for many years to clinically treat conditions associated with inflammatory bowel diseases, such as UC. However, the precise mechanisms behind its anti-inflammatory effects remain largely unknown. In this study, using the dextran sulfate sodium (DSS)-induced colitis mouse model, we evaluated the therapeutic effects of QHCY against UC and elucidated the possible underlying molecular mechanisms. We found that the administration of QHCY profoundly ameliorated DSS-induced clinical manifestations, colon shortening and histological damage in the mice with colitis. In addition, treatment with QHCY significantly decreased the DSS-induced secretion of serum amylase. Moreover, QHCY significantly inhibited the DSS-induced expression of TLR4 and myeloid differentiation primary response gene 88 (MyD88), the phosphorylation of IκB and the nuclear translocation of NF-κB. Taken together, our findings suggest that the suppression of the TLR4/NF-κB signaling pathway may be one of the mechanisms involved in the therapeutic effects of QHCY against UC.